1. Technical Field
The present invention relates to an optical substrate, an optical waveguide, and an optical waveguide substrate.
2. Related Art
As a conventional art, known is an optical waveguide substrate configured by: an optical waveguide in which a mirror surface having an angle of 45 degrees to the optical axis is disclosed in one end portion; a substrate in which the optical waveguide is disposed; a planar optical element which has a light emitting portion, and which is disposed on the substrate; and a flexible optical waveguide in which an end portion with a mirror surface having an angle of 45 degrees to the optical axis, and another end portion where a core is exposed are disposed (for example, see JP-A-2001-188146).
The optical waveguide is disposed so that the end portion having the mirror surface is directed toward the inner side of the substrate, and the other end is directed toward the outer side of the substrate. In the substrate, a groove is disposed at a position corresponding to the mirror surface.
An external force is applied to the flexible optical waveguide, so that the whole length of the waveguide is bent. The end portion where the core is exposed is caused to directly butt against the light emitting portion of the planer optical element, and bonded thereto. The end portion with the mirror surface is inserted into the groove disposed in the substrate, and optically connected to an end portion with a mirror surface in another optical waveguide.